Mercurial > hg > truffle
view src/share/vm/gc_implementation/shared/mutableSpace.cpp @ 3758:e2ce15aa3daf
Merge
author | never |
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date | Tue, 14 Jun 2011 15:20:55 -0700 |
parents | f95d63e2154a |
children | 20bfb6d15a94 |
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/* * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #ifndef SERIALGC #include "gc_implementation/shared/mutableSpace.hpp" #include "gc_implementation/shared/spaceDecorator.hpp" #include "oops/oop.inline.hpp" #include "runtime/safepoint.hpp" #include "runtime/thread.hpp" #endif MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) { assert(MutableSpace::alignment() >= 0 && MutableSpace::alignment() % os::vm_page_size() == 0, "Space should be aligned"); _mangler = new MutableSpaceMangler(this); } MutableSpace::~MutableSpace() { delete _mangler; } void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) { if (!mr.is_empty()) { size_t page_size = UseLargePages ? alignment() : os::vm_page_size(); HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size); HeapWord *end = (HeapWord*)round_down((intptr_t) mr.end(), page_size); if (end > start) { size_t size = pointer_delta(end, start, sizeof(char)); if (clear_space) { // Prefer page reallocation to migration. os::free_memory((char*)start, size); } os::numa_make_global((char*)start, size); } } } void MutableSpace::pretouch_pages(MemRegion mr) { for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) { char t = *p; *p = t; } } void MutableSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space, bool setup_pages) { assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()), "invalid space boundaries"); if (setup_pages && (UseNUMA || AlwaysPreTouch)) { // The space may move left and right or expand/shrink. // We'd like to enforce the desired page placement. MemRegion head, tail; if (last_setup_region().is_empty()) { // If it's the first initialization don't limit the amount of work. head = mr; tail = MemRegion(mr.end(), mr.end()); } else { // Is there an intersection with the address space? MemRegion intersection = last_setup_region().intersection(mr); if (intersection.is_empty()) { intersection = MemRegion(mr.end(), mr.end()); } // All the sizes below are in words. size_t head_size = 0, tail_size = 0; if (mr.start() <= intersection.start()) { head_size = pointer_delta(intersection.start(), mr.start()); } if(intersection.end() <= mr.end()) { tail_size = pointer_delta(mr.end(), intersection.end()); } // Limit the amount of page manipulation if necessary. if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) { const size_t change_size = head_size + tail_size; const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord; head_size = MIN2((size_t)(setup_rate_words * head_size / change_size), head_size); tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size), tail_size); } head = MemRegion(intersection.start() - head_size, intersection.start()); tail = MemRegion(intersection.end(), intersection.end() + tail_size); } assert(mr.contains(head) && mr.contains(tail), "Sanity"); if (UseNUMA) { numa_setup_pages(head, clear_space); numa_setup_pages(tail, clear_space); } if (AlwaysPreTouch) { pretouch_pages(head); pretouch_pages(tail); } // Remember where we stopped so that we can continue later. set_last_setup_region(MemRegion(head.start(), tail.end())); } set_bottom(mr.start()); set_end(mr.end()); if (clear_space) { clear(mangle_space); } } void MutableSpace::clear(bool mangle_space) { set_top(bottom()); if (ZapUnusedHeapArea && mangle_space) { mangle_unused_area(); } } #ifndef PRODUCT void MutableSpace::check_mangled_unused_area(HeapWord* limit) { mangler()->check_mangled_unused_area(limit); } void MutableSpace::check_mangled_unused_area_complete() { mangler()->check_mangled_unused_area_complete(); } // Mangle only the unused space that has not previously // been mangled and that has not been allocated since being // mangled. void MutableSpace::mangle_unused_area() { mangler()->mangle_unused_area(); } void MutableSpace::mangle_unused_area_complete() { mangler()->mangle_unused_area_complete(); } void MutableSpace::mangle_region(MemRegion mr) { SpaceMangler::mangle_region(mr); } void MutableSpace::set_top_for_allocations(HeapWord* v) { mangler()->set_top_for_allocations(v); } void MutableSpace::set_top_for_allocations() { mangler()->set_top_for_allocations(top()); } #endif // This version requires locking. */ HeapWord* MutableSpace::allocate(size_t size) { assert(Heap_lock->owned_by_self() || (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()), "not locked"); HeapWord* obj = top(); if (pointer_delta(end(), obj) >= size) { HeapWord* new_top = obj + size; set_top(new_top); assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top), "checking alignment"); return obj; } else { return NULL; } } // This version is lock-free. HeapWord* MutableSpace::cas_allocate(size_t size) { do { HeapWord* obj = top(); if (pointer_delta(end(), obj) >= size) { HeapWord* new_top = obj + size; HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); // result can be one of two: // the old top value: the exchange succeeded // otherwise: the new value of the top is returned. if (result != obj) { continue; // another thread beat us to the allocation, try again } assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top), "checking alignment"); return obj; } else { return NULL; } } while (true); } // Try to deallocate previous allocation. Returns true upon success. bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) { HeapWord* expected_top = obj + size; return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top; } void MutableSpace::oop_iterate(OopClosure* cl) { HeapWord* obj_addr = bottom(); HeapWord* t = top(); // Could call objects iterate, but this is easier. while (obj_addr < t) { obj_addr += oop(obj_addr)->oop_iterate(cl); } } void MutableSpace::object_iterate(ObjectClosure* cl) { HeapWord* p = bottom(); while (p < top()) { cl->do_object(oop(p)); p += oop(p)->size(); } } void MutableSpace::print_short() const { print_short_on(tty); } void MutableSpace::print_short_on( outputStream* st) const { st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K, (int) ((double) used_in_bytes() * 100 / capacity_in_bytes())); } void MutableSpace::print() const { print_on(tty); } void MutableSpace::print_on(outputStream* st) const { MutableSpace::print_short_on(st); st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")", bottom(), top(), end()); } void MutableSpace::verify(bool allow_dirty) { HeapWord* p = bottom(); HeapWord* t = top(); HeapWord* prev_p = NULL; while (p < t) { oop(p)->verify(); prev_p = p; p += oop(p)->size(); } guarantee(p == top(), "end of last object must match end of space"); }